Display device

ABSTRACT

A display device includes: a panel including a display screen and a side face that extends along a periphery of the display screen; a backlight located on a side of the panel opposite to the display screen to radiate light on the panel; a case, for containing the backlight, including a bottom that faces the panel with the backlight in between and a side wall that stands at a periphery of the bottom and faces the side face of the panel; and a combining member provided between the side face of the panel and the side wall to combine the panel and the case.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a Continuation of application Ser. No.15/499,052, filed Apr. 27, 2017, which claims the benefit of priority ofthe prior Japanese Patent Application No. 2016-127413, filed on Jun. 28,2016, the entire contents of which are incorporated herein by reference.

FIELD

The embodiments discussed herein relate to a display device.

BACKGROUND

In recent years, display devices are widely used in a smartphone, apersonal assistant device (PAD), a tablet computer, a car navigationsystem, and the like. There is a need for the display devices to maketheir display regions larger within the same housing size in order toachieve high-definition display, and therefore the frames of the displaydevices are narrowed by shortening the distance of a non-display partfrom an outer edge to a display region. Also, light leakage is preventedin the display devices.

See, for example, U.S. Patent Application Publication No. 2015/0241731.

SUMMARY

According to one aspect, there is provided a display device including: apanel including a display screen and a side face that extends along aperiphery of the display screen; a backlight located on a side of thepanel opposite to the display screen to radiate light on the panel; acase for containing the backlight, the case including a bottom thatfaces the panel with the backlight in between and a side wall thatstands at a periphery of the bottom and faces the side face of thepanel; and a combining member provided between the side face of thepanel and the side wall to combine the panel and the case.

The object and advantages of the invention will be realized and attainedby means of the elements and combinations particularly pointed out inthe claims.

It is to be understood that both foregoing general description and thefollowing detailed description are exemplary and explanatory and are notrestrictive of the invention.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a plan view of a display device in a first embodiment;

FIG. 2 is an exploded perspective view of a display device in the firstembodiment;

FIG. 3 is an exploded perspective view of a panel in the firstembodiment;

FIG. 4 is an exploded perspective view of a backlight in the firstembodiment;

FIG. 5 is a perspective view of a case in the first embodiment;

FIG. 6 is a partial cross-sectional view of a display device in thefirst embodiment;

FIGS. 7A to 7C illustrate exemplary variants of a panel in the firstembodiment;

FIG. 8 is a partial cross-sectional view of an exemplary variant of adisplay device in the first embodiment;

FIGS. 9A and 9B illustrate a combining member in a second embodiment;and

FIG. 10 is a partial cross-sectional view of a display device in thesecond embodiment.

DESCRIPTION OF EMBODIMENTS

Several embodiments will be described below with reference to theaccompanying drawings, wherein like reference numerals refer to likeelements throughout.

Note that the disclosure is just an example, and as a matter of coursethe scope of the present embodiments includes alteration that theskilled person can easily conceive of as appropriate without deviatingfrom the spirit of the embodiments. Also, in order to make thedescription clearer, the drawings are depicted schematically with regardto width, thickness, shape, etc. of each component, as compared with anactual form, but the drawings are just an example and do not limit theinterpretation of the present embodiments.

Also, in the present embodiments and the drawings, the same elements asthose described with reference to aforementioned drawings are denotedwith the same reference signs, and their detailed description is omittedas appropriate in some cases.

First Embodiment

First, a display device of a first embodiment will be described. FIG. 1is a plan view of a display device in the first embodiment, which isseen from a front surface (a surface for displaying an image) side. FIG.2 is an exploded perspective view of the display device in the firstembodiment. Note that, in the following description, a front surface ofeach component faces toward a direction in which the display devicedisplays an image (upward of FIG. 2), and a back surface is an oppositeside (downward of FIG. 2) to the front surface.

As illustrated in FIG. 2, a display device 10 is a transmissive displaydevice that includes a cover panel 100, a bonding member 110, a liquidcrystal panel (panel, hereinafter) 120, and a backlight unit 130.

A glass plate of the cover panel 100 is formed into a rectangular shapewith four round corners and covers and protects a display screen 120 awhich is a front surface of the panel 120. Also, the cover panel 100 issized such that a periphery (outer edge) of the cover panel 100protrudes outwardly from a periphery of the panel 120 in the plan view.

The cover panel 100 includes a transmission section 101 and aframe-shaped light blocking section 102 that surrounds a periphery ofthe transmission section 101. The transmission section 101 is a regionthat faces a display region 120 b of the panel 120 and allow light totransmit therethrough. The light blocking section 102 is a region formedand provided with a light blocking member 102 a for blocking light at aback surface side of the glass plate. Note that the light blockingsection 102 is also referred to as a frame region of the display device10. Note that the light blocking member 102 a may be formed at a frontsurface side of the glass plate.

The bonding member 110 bonds the cover panel 100 to the display screen120 a of the panel 120. The bonding member 110 has high transparency andbonding property (adherence property) and is an ultraviolet curableresin (UV resin) for example. The bonding member 110 is formed in arectangular shape in the plan view.

The panel 120 is a flat plate display device that displays an image, andincludes a display region 120 b that displays an image and a frameregion 120 c that surrounds a periphery of the display region 120 b. Thepanel 120 has a transmission display function for displaying (forming)an image on the display screen 120 a by selectively transmitting thelight from the backlight unit 130 to the display region 120 b.

Here, the panel 120 will be described more specifically with referenceto FIG. 3. FIG. 3 is an exploded perspective view of the panel in thefirst embodiment.

The panel 120 operates in a main display mode that is a lateral electricfield mode that utilizes a lateral electric field substantially parallelto a substrate main surface. Note that the panel 120 may be configuredto mainly operate in a vertical electric field mode that utilizes avertical electric field substantially perpendicular to the substratemain surface.

The panel 120 includes an upper substrate 121, a lower substrate 122, apolarizer 123, a polarizer 124, and a drive control flexible printedcircuit (FPC) 125.

The upper substrate 121 and the lower substrate 122 are a pair ofsubstrates that sandwich a liquid crystal. The upper substrate 121 is arectangular flat plate on which color filters of red (R), green (G), andblue (B) are formed corresponding to pixels. The lower substrate 122 isa rectangular flat plate on which thin-film transistors are formed.

The polarizer 123 is located at an upper surface side (front surfaceside) of the upper substrate 121 and is attached to the upper substrate121 to polarize the light emitted from the panel 120. The polarizer 124is located at a lower surface side (back surface side) of the lowersubstrate 122 and is attached to the lower substrate 122 to polarize thelight from the back light unit 130.

The drive control FPC 125 is a circuit substrate provided with asemiconductor element such as an IC chip, and supplies a signal fordriving the panel 120. The drive control FPC 125 is attached to thelower substrate 122 and extends outwardly from an edge of the lowersubstrate 122 in the plan view. In accordance with the signal suppliedfrom the drive control FPC 125, the panel 120 selectively transmits thelight from the backlight unit 130 to the display region 120 b anddisplays an image on the display screen 120 a. The description continueswith reference to FIGS. 1 and 2 again.

The backlight unit 130 is located at a back surface side of the panel120 and outputs light to the display region 120 b on the back surface ofthe panel 120. The backlight unit 130 includes a backlight 140 thatoutputs light and a case 150 formed of metal (light blocking member) forcontaining the backlight 140.

Here, the backlight 140 and the case 150 will be described specificallywith reference to FIGS. 4 and 5. FIG. 4 is an exploded perspective viewof the backlight in the first embodiment. FIG. 5 is a perspective viewof the case in the first embodiment.

As illustrated in FIG. 4, the backlight 140 includes a light guide plate141, light sources 142 a, 142 b, . . . , 142 n, a light source controlFPC 143, a reflector 144, a diffuser 145, and a prism sheet 146.

The light guide plate 141 is rectangular in the plan view and diffusesthe light that has entered from one side face (hereinafter, referred toas light entrance surface) among four side faces and outputs uniformlight from a front surface (hereinafter, referred to as light outputsurface) toward the back surface of the panel 120. The light is outputtoward the panel 120 and enters the panel 120 from the back surface.Note that the light entrance surface is provided at the side at whichthe drive control FPC 125 of the panel 120 is located at the time ofassembly.

The light sources 142 a, 142 b, . . . 142 n are located on the lightsource control FPC 143 along the light entrance surface and emits lighttoward the light entrance surface. The light sources 142 a, 142 b, . . ., 142 n are light emitting diodes (LEDs).

The light source control FPC 143 is a circuit substrate that extendsalong the light entrance surface of the light guide plate 141 andsupplies signals to drive the light sources 142 a, 142 b, . . . , 142 n.A part of the light source control FPC 143 protrudes toward the oppositeside to the light entrance surface in the plan view. The protruding partextends outwardly from the case 150 that is containing the backlight140. In accordance with the signal supplied from the light sourcecontrol FPC 143, the backlight 140 controls the light sources 142 a, 142b, . . . , 142 n to adjust the light that enters the light guide plate141, and radiates the light of desired intensity on the back surface ofthe panel 120.

The reflector 144 is located at the back surface side of the light guideplate 141 and covers the entire surface of the back surface. Thereflector 144 has functions such as reflection, diffusion, andscattering and returns the light from the back surface side of the lightguide plate 141 to the light guide plate 141. Thereby, the light thathas entered the light guide plate 141 from the light sources 142 a, 142b, . . . , 142 n can be utilized efficiently and contribute to improvethe brightness of the light emitted from the backlight 140.

The reflector 144 is foamed polyethylene terephthalate (PET), forexample. Note that a silver vapor deposition film, a multilayerreflection film, a white PET, or the like can be used as the reflector144.

The diffuser 145 is a transmissive optical member located at the lightoutput surface side of the light guide plate 141 and adjusts an opticalproperty of the light from the light guide plate 141. The prism sheet146 is a transmissive optical member located at the front surface sideof the diffuser 145 and adjusts an optical property of the light thathas transmitted through the diffuser 145. Note that the diffuser 145 andthe prism sheet 146 are examples of the optical sheet that adjusts theoptical property of the light emitted from the light output surface ofthe light guide plate 141.

Next, the case 150 will be described. As illustrated in FIG. 5, the case150 has a rectangular box shape and includes a bottom 151 and side walls152 to 155.

The bottom 151 is positioned at the back surface side of the backlight140 when the backlight 140 is contained. The bottom 151 is rectangularin the plan view. The bottom 151 is sized slightly larger than thebacklight 140 and the panel 120 and smaller than the cover panel 100 inthe plan view.

The side walls 152 to 155 stand at the periphery of the bottom 151 andare formed along the entire periphery of the bottom 151. Morespecifically, the side walls 152 and 154 are formed along the entirelong edges of the bottom 151. The side walls 153 and 155 are formedalong the entire short edges of the bottom 151.

The heights from the bottom 151 of the side walls 152 to 155 areslightly larger than the sum of the thickness of the backlight 140 andthe thickness of the panel 120.

The side wall 153 includes the FPC passing portion 153 a and the FPCpassing portion 153 b. The FPC passing portion 153 a is formed in astepwise manner at an opposite side of the side wall 153 to the bottom151 (in a recessed manner toward the bottom in a part of the side wall153). The FPC passing portion 153 a allows the drive control FPC 125 toextend therethrough to the outside of the case 150. The FPC passingportion 153 b is formed in a stepwise manner at the opposite side of theside wall 153 to the bottom 151 (in a recessed manner toward the bottomin a part of the side wall 153). The FPC passing portion 153 b allowsthe light source control FPC 143 to extend therethrough to the outsideof the case 150.

Also, these FPC passing portions 153 a and 153 b may be formed asopenings that are formed in a part of the side wall 153 or from the sidewall 153 to the bottom 151.

Note that the backlight unit 130 and the panel 120 are located in thisorder at the front surface side of the bottom 151 of the case 150, andthus the FPC passing portion 153 b is formed deeper than the FPC passingportion 153 a.

Next, a cross-sectional structure of the display device will bedescribed. FIG. 6 is a partial cross-sectional view of the displaydevice in the first embodiment and illustrates an A-A cross-sectionalview of the display device illustrated in FIG. 1.

As illustrated in FIG. 6, the side wall 154 of the case 150 faces theside face 120 d of the panel 120 in the display device 10. Moreover, acombining member 160 is provided in a gap between the side wall 154 andthe side face 120 d to combine (join) the panel 120 and the case 150.The combining member 160 is hot-melt curable bonding adhesive thatblocks light. Note that the combining member 160 may be thermosettingbonding adhesive, photocurable bonding adhesive, ultraviolet curablebonding adhesive, or the like, instead of the hot-melt curable bondingadhesive.

Note that the side face 120 d (outer circumferential portion) thatextends along the periphery of the display screen 120 a includes atleast the side faces of the polarizers 123 and 124 and the side faces ofthe paired substrates 121 and 122, and when the side faces of thepolarizers 123 and 124 are away from the side faces of the pairedsubstrates, includes in-between surfaces. For example, in the presentembodiment, the side face include a part of the upper substrate 121 inbetween the side face of the polarizer 123 and the side face of theupper substrate 121, and a part of the lower substrate 122 in betweenthe side face of the polarizer 124 and the side face of the lowersubstrate 122. Note that, as illustrated in FIGS. 7A to 7C describedlater, when a polarizer protrudes from the side faces of the pairedsubstrates 121 and 122, the side face of the panel 120 includes a partof the polarizer in between the side face of the polarizer and the sidefaces of the paired substrates 121 and 122.

Also, the side face (outer circumferential portion) of the backlight 140includes the side faces of the components of the backlight 140 (in thepresent embodiment, the prism sheet 146, the diffuser 145, the lightguide plate 141, and the reflector 144) and in-between surfaces whenthese side faces are away from each other. For example, in the presentembodiment, the side face includes a part of the diffuser 145 in betweenthe side face of the light guide plate 141 and the side face of thediffuser 145, and a part of the reflector 144 in between the side faceof the light guide plate 141 and the side face of the reflector 144.

When the case 150 and the panel 120 are combined at the side face 120 das described above, the distance from the periphery of the displayscreen 120 a to the display region 120 b of the panel 120 is madeshorter in the display device 10. That is, the display device 10 isconfigured with the large display region 120 b and the narrow frame.

Here, a comparative example in which the back surface of the panel iscombined with the case will be described. When the back surface of thepanel is combined with the case by providing a frame between theperiphery of the back surface side of the panel and the bottom of thecase in such a manner that the front surface side of the frame iscombined with the panel and the back surface side of the frame iscombined with the case, the display device is provided with a combiningmember at the periphery of the back surface of the panel. Note that adouble-faced adhesive tape or the like is used as the combining memberprovided in the front surface side and the back surface side of theframe.

If the combining member overlaps the display region in the plan view,the combining member is recognized by a person who looks into thedisplay region, and it is concerned to affect the display quality.Hence, it is not preferable to locate the combining member at a partthat overlaps the display region. Thus, when the back surface of thepanel is combined with the case, a part of the display screencorresponding to the location of the combining member is used as theframe region (non-display region).

That is, when the back surface of the panel is fixed to the case, thedisplay region is set inside the part corresponding to the location ofthe combining member. Also, in order to achieve a predeterminedcombining strength, the display device needs to have a combining memberof a certain width or more, and it is difficult to reduce the width ofthe combining member to narrow the frame.

On the other hand, the side face 120 d of the panel 120 is combined withthe case 150 in the display device 10. Hence, the display region 120 bcan be set without a restriction that the combining member 160 does notoverlap the display region 120 b as in the above comparative example.

Hence, in this display device 10, the distance from the periphery of thedisplay screen 120 a to the display region 120 b of the panel 120 isshortened, and it leads to enlarging the display region 120 b. That is,the display device 10 has the narrow frame.

Also, the side face 120 d of the panel 120 and the side wall 154 of thecase 150 are combined by the combining member 160, and thus the lightleakage from the gap is curbed in the display device 10. The displaydevice 10 displays an image in the display region 120 b by the lightoutput from the backlight 140 and transmitting through the displayregion 120 b. If the light were output from the side face 120 d orproceeded to the gap between the side face 120 d and the side wall 154without entering the panel 120, the light would leak from the gap. As aresult, it would be concerned to affect the display, exteriorappearance, etc.

To prevent this, in the display device 10, the side face 120 d of thepanel 120 and the side wall 154 of the case 150 are entirely combined bythe combining member 160. More specifically, the gap between the case150 and the side wall 154 is filled by the light blocking combiningmember 160. Hence, even when the light reaches the side face 120 d, thelight leakage is prevented by the combining member 160. Also, in thedisplay device 10, the side face 120 d and the side wall 154 arecombined by using the combining member 160, and thus even when the lightreaches the gap between the side face 120 d and the side wall 154, thelight leakage is prevented by the combining member 160. In particular,the light blocking bonding adhesive is used as the combining member 160in the display device 10, and thus the light leakage is preventedunfailingly.

Also, the display device 10 is provided with the combining member 160 inthe gap between the side face 120 d and the side wall 154, and therebythe side face 120 d is shielded (protected) with the combining member160 to improve its impact resistance.

Further, in the display device 10, the gap between the side face 120 dand the side wall 154 is covered by combining the side face 120 d andthe side wall 154, thereby preventing entry of dust and moisture toimprove its reliability.

Also, the display device 10 uses the hot-melt curable bonding adhesiveas the combining member 160 to firmly combine the panel 120 and the case150. As illustrated in FIG. 6, the side face 120 d is composed of theside faces of a plurality of stacked members, and thus is not flat butincludes steps. Specifically, in the display device 10 illustrated inFIG. 6, the side face 120 d includes the part corresponding to the sidefaces of the upper substrate 121 and the lower substrate 122 whichprotrudes from the part corresponding to the side faces of thepolarizers 123 and 124.

With regard to this, the display device 10 uses the hot-melt curablebonding adhesive as the combining member 160. The combining member 160is fitted to the steps (conformed to the steps) and thereafter cured,and thereby the steps are filled with the combining member 160. Also,the steps increases the bonding area, and therefore the display device10 increases the combining force of the combining member 160 to combinethe panel 120 and the case 150 more firmly.

Also, in the display device 10 illustrated in FIG. 6, the backlight 140faces the panel 120 at the frame region 120 c via an air gap only.Thereby, light is radiated on the panel 120 from the part of thebacklight 140 positioned under the frame region 120 c, preventingdecrease of brightness in the periphery of the display region 120 b(vicinity of the boundary between the display region 120 b and the frameregion 120 c) of the display device 10.

Also, as illustrated in FIG. 6, the backlight 140 is contained in thecase 150, with the side face of the backlight 140 protruding beyond theside face 120 d of the panel 120 toward the side wall 154. To configurelike this, it is preferable that the size between the long edges of thebacklight 140 be larger than the size between the long edges of thepanel 120. Thereby, the light from the backlight 140 is radiated even onthe periphery of the side face 120 d of the panel 120, therebypreventing the decrease of the brightness.

Note that the side face 120 d is joined to the side wall 154 with thecombining member 160 in between, and thus a space is provided below thecombining member 160. Hence, the side face of the backlight 140 canprotrude into the space, and thus in the present embodiment thebacklight 140 can be enlarged to an extent that the side face of thebacklight 140 overlap the combining member 160 in the plan view. Notethat the side face of the backlight 140 faces the side wall 154 througha gap.

Note that the display device 10 is not limited to the aboveconfiguration but can employ a configuration in which the side face 120d of the panel 120 protrudes beyond the side face of the backlight 140.

Here, a procedure for combining the panel 120 and the side wall 154 willbe described. First, bonding adhesive (the combining member 160) that isheated and melted is applied on the side face 120 d. Thereafter,positioning of the panel 120 and the case 150 is performed by moving thepanel 120 to a combined position (hereinafter, a regular position) inthe case 150. Thereafter, the bonding adhesive is cooled and solidified,and the panel 120 and the case 150 are combined at the regular position.

As described above, the bonding adhesive is applied on the side face 120d in consideration of the steps (for example, more bonding adhesive isapplied on a recessed portion than on a protruding portion in advance)in order to prevent generation of a gap between the side face 120 d andthe side wall 154 in the display device 10.

Also, in the display device 10 illustrated in FIG. 6, the backlight 140is located with a gap between the optical sheets (the prism sheet 146and the diffuser 145) and the side wall 154. Also, in the display device10, the combining member 160 is located with a gap between the combiningmember 160 and the optical sheets.

In general, the optical sheets stretch according to its environment, insome cases. Hence, in the display device 10, a stretchable region isprovided between the optical sheets and the side wall 154, and a gap isprovided between the combining member 160 and the optical sheets,thereby preventing their contact and ensuring stretch of the opticalsheets.

For example, if the optical sheets were combined with the combiningmember 160 or were in contact with the side wall 154, it would beconcerned that the optical sheets warp when stretching. It would beconcerned that this warp changes the optical property of the lightoutput from the backlight 140 and affects the display quality.

With regard to this, in the display device 10, the freedom degree of thestretch is ensured by providing the stretchable region, and therebyprevents the warp of the sheets and the adverse effect on the displayquality.

Note that, in the display device 10 illustrated in FIG. 6, the gap isprovided between the panel 120 and the backlight 140, but this is not alimitation. The panel 120 and the backlight 140 may be in contact witheach other. With the panel 120 in contact with the backlight 140, thedisplay device 10 can be made thinner by the size of the gap providedbetween the backlight 140 and the panel 120.

In this case, it is preferable that a hard coat layer be provided on theback surface of the panel 120 (more specifically, the back surface ofthe polarizer). With the hard coat layer provided on the back surface ofthe panel 120, the display device 10 can prevent the prism sheet 146from damaging the polarizer 124. Thus, in the display device 10,deterioration of the display quality due to the contact between thebacklight 140 and the panel 120 is prevented.

Note that the side wall 154 may face only a part of the side face 120 din the cross-sectional view. In this case as well, light leakage isprevented by providing the bonding adhesive (the combining member 160)not only between the side face 120 d and side wall 154, but also at apart that does not face the side wall 154, in the same way as when theside wall 154 faces the entire surface.

However, it is preferable that a tip portion of the side wall 154 thatis opposing the bottom 151 extend (protrude) beyond the side face 120 dto an upper end side (upward of FIG. 6) so as to face the entire surfaceof the side face 120 d in the cross-sectional view. In this case, in thedisplay device 10, the entire surface of the side face 120 d is combinedwith the side wall 154 by the combining member 160, and thereby thecombining strength between the panel 120 and the case 150 isstrengthened.

Although the A-A cross section (the right edge part of FIG. 1) of thedisplay device 10 has been described, the upper edge part and the leftedge part of FIG. 1 of the display device 10 can be structured in thesame way as FIG. 6. Also, a part other than the FPC passing portions 153a and 153 b in the lower edge part can be structured in the same way asFIG. 6.

Note that, in general, the left and right edge parts adjacent to thelocation (lower edge part of FIG. 1) of the drive control FPC 125 andthe light source control FPC 143 are desired to be narrow as a frame,and thus only the left and right edge parts may be structured in thesame way as FIG. 6.

Note that, in the configuration of the present embodiment, the case 150is combined with the panel 120, but the backlight 140 is not combinedwith the case 150 and the panel 120 in any of 3 edges of the frameregion excluding one edge of the IC arrangement side. In contrast, aconfiguration in which the backlight 140 is joined with the case 150 andthe panel 120 at one or two edges of the frame region can be employed.This case also employs a configuration in which, at the remaining edges,the side face 120 d is joined to the side wall 154 with the combiningmember 160, and the backlight 140 is not joined to either of the case150 and the panel 120 as in the present embodiment. Note that aconfiguration in which each component of the backlight 140 is joinedwith the case 150 and the panel 120 at the IC arrangement side can beemployed.

[First Exemplary Variant]

Next, first exemplary variants will be described with reference to FIGS.7A to 7C. FIGS. 7A to 7C illustrate exemplary variants of the panel ofthe first embodiment in partial cross sections corresponding to FIG. 6.Note that cross sections of a part excluding the cover panel 100 and thebonding member 110 are illustrated for simplicity of the drawings.

In a panel 220, illustrated in FIG. 7A, a polarizer 123 a and apolarizer 124 a are used instead of the polarizers 123 and 124. Thepolarizer 123 a and the polarizer 124 a are sized such that the sidefaces of the polarizer 123 a and the polarizer 124 a are aligned withthe side face of the upper substrate 121 and the side face of the lowersubstrate 122. Hence, a side face 220 d of the panel 220 is composed ofthe side face of the polarizer 123 a, the side face of the polarizer 124a, the side face of the upper substrate 121, and the side face of thelower substrate 122, which are formed planar (flat).

Thereby, the upper substrate 121 and the lower substrate 122 do notoverlap the combining member 160 in the plan view, and thus the panel220 can effectively utilize the light from the backlight 140 even at thevicinity of the side faces of the upper substrate 121 and the lowersubstrate 122. This prevents the brightness from decreasing at theperiphery of the display region (the vicinity of the boundary betweenthe display region and the frame region) in the panel 220.

In a panel 320, illustrated in FIG. 7B, a polarizer 124 b is usedinstead of the polarizer 124 a. The polarizer 124 b is sized such thatthe side face of the polarizer 124 b protrudes from the side face of thepolarizer 123 a, the side face of the upper substrate 121, and the sideface of the lower substrate 122. Hence, a side face 320 d of the panel320 is composed of the side face of the polarizer 123 a, the side faceof the upper substrate 121, the side face of the lower substrate 122, apart of the polarizer 124 b in between the side face of the lowersubstrate 122 and the side face of the polarizer 124 b, and the sideface of the polarizer 124 b.

Thereby, the upper substrate 121 and the lower substrate 122 do notoverlap the combining member 160 in the plan view, and thus the panel320 can effectively utilize the light from the backlight 140 even at thevicinity of the side faces of the upper substrate 121 and the lowersubstrate 122. Also, the side face of the polarizer 124 b protrudes, andthus even if the combining member 160 gets onto the back surface side ofthe polarizer 124 b, the upper substrate 121 and the lower substrate 122are prevented from overlapping the combining member 160 in the planview. This prevents the brightness from decreasing at the periphery inthe panel 320. Further, the polarizer 124 b is shaped to bite into thecombining member 160 at the side face 320 d of the panel 320, and thusthe panel 320 increases its contact surface area between the side face320 d and the combining member 160 as well as the combining strengthwith the case 150.

In a panel 420, illustrated in FIG. 7C, a polarizer 123 b is usedinstead of the polarizer 123 a. The polarizer 123 b is sized such thatthe side face of the polarizer 123 b protrudes from the side face of theupper substrate 121, the side face of the lower substrate 122, and theside face of the polarizer 124 a. Hence, a side face 420 d of the panel420 is composed of the side face of the polarizer 123 b, a part of thepolarizer 123 b in between the side face of the polarizer 123 b and theside face of the upper substrate 121, the side face of the uppersubstrate 121, the side face of the lower substrate 122, and the sideface of the polarizer 124 a.

Thereby, the upper substrate 121 and the lower substrate 122 do notoverlap the combining member 160 in the plan view, and thus the panel420 can effectively utilize the light from the backlight 140 even at thevicinity of the side faces of the upper substrate 121 and the lowersubstrate 122. Also, the side face of the polarizer 123 b protrudes, andthus even if the combining member 160 gets onto the front surface sideof the polarizer 123 b, the upper substrate 121 and the lower substrate122 are prevented from overlapping the combining member 160 in the planview. This prevents the brightness from decreasing at the peripheryportion in the panel 420. Further, the polarizer 123 b is shaped to biteinto the combining member 160 at the side face 420 d of the panel 420,and thus the panel 420 increases its contact surface area between theside face 420 d and the combining member 160 as well as the combiningstrength with the case 150.

Note that other effects which are achieved by the modes described in thepresent embodiment and are obvious from the description of the presentspecification or reached by those skilled in the art as appropriate areinterpreted as being achieved by the present disclosure as a matter ofcourse.

[Second Exemplary Variant]

Next, a second exemplary variant will be described with reference toFIG. 8. FIG. 8 is a partial cross-sectional view of an exemplary variantof the display device in the first embodiment and illustrates a partialcross section corresponding to FIG. 6.

As illustrated in FIG. 8, the display device 20 includes a cover panel100, a bonding member 110, a panel 120, and a backlight unit 230. Thebacklight unit 230 includes a backlight 240 that is the backlight 140from which a reflector is removed, and a case 250 formed of a memberthat reflects light (for example, a reflector). The case 250 is formedby performing a bending process or vacuum forming on a reflector, forexample. In the backlight unit 230, the light guide plate 141 of thebacklight 240 is located directly on the front surface of the bottom251.

As described above, the case 250 is formed of the member that reflectslight in order to provide a light reflecting function, and the reflectoris not located in the backlight 240, so that the display device 20 canbe made thinner by the thickness of the reflector.

Although, in the above description, the case 250 is formed in arectangular box shape by performing a bending process or vacuum formingon the member that reflects light (for example, a reflector) to provideboth functions of the case and the reflector, this is not a limitation.For example, the front surface of the bottom 251 may be processed toreflect light (for example, mirror finishing) to provide both functionsof the case and the reflector.

Note that other effects which are achieved by the modes described in thepresent embodiment and are obvious from the description of the presentspecification or reached by those skilled in the art as appropriate areinterpreted as being achieved by the present disclosure as a matter ofcourse.

Second Embodiment

In the first embodiment, the hot-melt curable bonding adhesive is usedas the combining member. On the other hand, a double-faced adhesive tapeis used in a second embodiment instead of the hot-melt curable bondingadhesive. The second embodiment will be described specifically withreference to FIGS. 9A, 9B, and 10.

FIGS. 9A and 9B illustrate a combining member in the second embodiment.FIG. 9A is a plan view of a bonding surface of the combining member seenfrom a normal direction, and FIG. 9B is a B-B cross-sectional view. FIG.10 is a partial cross-sectional view of a display device in the secondembodiment and illustrates a partial cross section, corresponding toFIG. 6, of the display device in the second embodiment.

As illustrated in FIG. 9B, a combining member 260 includes a lightblocking base material 261, a light blocking bonding adhesive 262 aapplied on a bonding surface 261 a of the base material, and a lightblocking bonding adhesive 262 b applied on a bonding surface 261 b ofthe base material 261. The base material 261 has a cushioning propertyand is transformable acrylic foam. Note that urethane foam, a memberthat expands with moisture absorption, a member that expands with heat,and the like may be used as the transformable base material having acushioning property, for example.

Although the base material 261 and the bonding adhesives 262 a and 262 bblock light, the combining member 260 as a whole may block light.Specifically, any one of the base material 261 and the bonding adhesives262 a and 262 b is needless to block light.

As illustrated in FIG. 10, a display device 30 is configured such thatthe side face 120 d and the side wall 154 are combined by using thecombining member 260. When the side face 120 d and the side wall 154 arecombined with the combining member 260, a part of the base material 261corresponding to the upper substrate 121 and the lower substrate 122 ofthe panel 120 is dented with elastic deformation.

As described above, the base material 261 of the combining member 260transforms to change its shape according to the shape of the side face120 d, and thus the combining member 260 is located without a gap at thesteps in the same way as the first embodiment. Also, the steps enlargethe bonding area, and therefore the combining force of the combiningmember 260 is increased to combine the panel 120 and the case 150 morefirmly. Also, the base material 261 has the cushioning property, andthus the display device 30 can improve its impact resistance.

Here, a combining procedure of the panel 120 and the side wall 154 whena double-faced adhesive tape is used will be described. First, adouble-faced adhesive tape is attached to a position on the side wall154 of the case 150 to which the panel 120 is fixed. Thereafter, thepanel 120 is pressed into the case 150 so as to transform the basematerial 261 according to the shape of the side face 120 d, and is movedto a regular position in the case 150. Thereafter, the bonding adhesiveis solidified to combine the panel 120 and the case 150 at the regularposition.

The above is the second embodiment. Note that the same effects as theaforementioned first embodiment can be obtained in the second embodimentas well.

Also, other effects which are achieved by the modes described in thepresent embodiment and are obvious from the description of the presentspecification or reached by those skilled in the art as appropriate areinterpreted as being achieved by the present disclosure as a matter ofcourse.

Note that the display device described in each embodiment can beintegrated and used in various types of electronic devices, such as asmartphone, a tablet terminal, a mobile phone, a notebook PC, a portablegame machine, an electronic dictionary, a television device, and a carnavigation system.

All examples and conditional language provided herein are intended forthe pedagogical purposes of aiding the reader in understanding theinvention and the concepts contributed by the inventor to further art,and are not to be construed as limitations to such specifically recitedexamples and conditions, nor does the organization of such examples inthe specification relate to a showing of the superiority and inferiorityof the invention. Although one or more embodiments of the presentinvention have been described in detail, it should be understood thatvarious changes, substitutions, and alterations could be made heretowithout departing from the spirit and scope of the invention.

What is claimed is:
 1. A display device comprising: a first substratehaving a first main surface and a first side surface intersecting thefirst main surface, and a combining member on the first side surface,wherein the combining member is located on a first outer edge part ofthe first main surface, the first side surface continuously.
 2. Thedisplay device according to claim 1, further comprising a backlightunit, wherein a part of the combining member is located between thefirst main surface and the backlight unit.
 3. The display deviceaccording to claim 1, further comprising a backlight unit, wherein thefirst main surface is at an opposite side of the first substrate fromthe backlight unit.
 4. The display device according to claim 1, furthercomprising a display screen above the first substrate, wherein the firstmain surface is at an opposite side of the first substrate from thedisplay screen.
 5. The display device according to claim 1, furthercomprising a display screen above the first substrate, wherein the firstmain surface is located at a side of the display screen.
 6. The displaydevice according to claim 1, further comprising a second substratefacing the first substrate, wherein the second substrate has a secondmain surface and a second side surface intersecting the second mainsurface, and the combining member is located on the firs side surfaceand the second side surface continuously.
 7. The display deviceaccording to claim 1, wherein a first polarizer is on the first mainsurface, and the combining member is in contact with the firstpolarizer.
 8. The display device according to claim 7, wherein the firstpolarizer has a third main surface and a third side surface, the thirdmain surface is at an opposite side of the first polarizer from thefirst substrate, and the combining member is in contact with the thirdside surface, and is not in contact with the third main surface.
 9. Thedisplay device according to claim 1, further comprising a casecontaining the first substrate, wherein the case includes a bottom and aside wall, the side wall faces the first side surface, and the combiningmember attaches the first substrate to the side wall.
 10. The displaydevice according to claim 9, wherein an air gap is located between thecombining member and the bottom of the case.
 11. The display deviceaccording to claim 1, wherein the combining member is a bondingadhesive.
 12. The display device according to claim 1, wherein thecombining member is a double-faced adhesive tape.
 13. The display deviceaccording to claim 1, further comprising an optical sheet, wherein amain surface of the optical sheet has a portion overlapping with thecombining member in a plan view and not overlapping with the firstsubstrate in a plan view.
 14. A display device comprising: a firstsubstrate having a first main surface and a first side surfaceintersecting the first main surface, and a combining member on the firstside surface, wherein the combining member is located on the first sidesurface and a part of the first main surface continuously.
 15. Thedisplay device according to claim 14, further comprising a backlightunit, wherein a part of the combining member is located between thefirst main surface and the backlight unit.
 16. The display deviceaccording to claim 14, further comprising a backlight unit, wherein thefirst main surface is at an opposite side of the first substrate fromthe backlight unit.
 17. The display device according to claim 14,further comprising a display screen above the first substrate, whereinthe first main surface is at an opposite side of the first substratefrom the display screen.
 18. The display device according to claim 14,further comprising a display screen above the first substrate, whereinthe first main surface is located at a side of the display screen. 19.The display device according to claim 14, further comprising a secondsubstrate facing the first substrate, wherein the second substrate has asecond main surface and a second side surface intersecting the secondmain surface, and the combining member is located on the firs sidesurface and the second side surface continuously.
 20. The display deviceaccording to claim 14, further comprising an optical sheet, wherein amain surface of the optical sheet has a portion overlapping with thecombining member in a plan view and not overlapping with the firstsubstrate in a plan view.